So-called conventional rakes have a single row of tines integral with and extending from a back bar, and it may be stated that as a general rule the tines of such a conventional rake are curved, relatively thin or narrow, are widely spaced apart and are long. These known rakes have proven to be satisfactory in doing the job ordinarily expected of a conventional rake. However, there are many kinds of work that are better carried out with more efficiency if the use of the long, thin tines is avoided and relatively wider and more closely spaced teeth are used.
Because of this condition rakes have been provided which present two rows of teeth in back-to-back relation. However, in the known rakes of this character, the two rows of teeth are integrally joined usually by being extended from a common back bar. Such rakes have met with little or no public acceptance because the user must always manipulate both rows of tines and the weight of the unused row amounts to nothing more than an impediment to the conventional raking operation.
Because of the foregoing unsatisfactory condition, it has been proposed to provide an attachment that is applied to a rake to convert it to one having two rows of tines or teeth. Such devices have also met with little public approval due mainly to the fact that the basic rake, if it can be said to be curved, is of special construction and it is not practical to provide a conversion kit for only such specially constructed rakes.
Before this application was filed in the Patent and Trademark Office, a patentability search was conducted which brings to light the following patents as those found which are believed to come closest to the subject conversion kit attachment:
Gilbert; U.S. Pat. No. 838,100
Pihl; U.S. Pat. No. 1,800,103
Sawyer; U.S. Pat. No. 2,010,325
Loree; U.S. Pat. No. 607,383
Kropp; U.S. Pat. No. 938,001
Rundberg; U.S. Pat. No. 1,352,386
Ritchie; U.S. Pat. No. 1,191,911
Carkey; U.S. Pat. No. 1,632,883.
A brief comment is made on the more pertinent of these patents as follows: